Many electronic devices have components that include an integrated memory. Often, the manufacturer of these devices wants to monitor usage to determine a remaining life of the device. One example of these devices is a printer having a memory on a printing cartridge.
Printers, such as inkjet printers or electrostatic printers, print an image on a recording medium by dispensing a printing medium onto the recording medium. Ink jet printers operate by ejecting ink drops from a printhead onto the recording medium. The printhead may contain one or more supplies of ink or be connected to separate ink cartridges that supply ink. Color images are formed by ejecting color inks onto the recording medium from one or more print heads. One printhead is used to eject black ink and a second printhead is used to eject color ink. Alternatively, each color ink may be ejected by single printhead. Electrostatic or laser printers form an image on a recording medium by transferring toner particles onto the medium. Typically, a recording drum is charged and a latent image is formed on the drum by a laser. The latent image is developed on the drum by developer or toner particles and this image is transferred directly or indirectly onto a recording medium. In color printers multiple cartridges are provided to transfer color images.
An example of an image recording device is described in U.S. Pat. No. 7,844,786. In this device, page counts recorded by non-volatile memory modules (“memory modules”) may be incremented as pages are printed. Page counts may include the total number of pages printed by a printer and the total number of pages printed for each of a number of print categories. Recording the number of pages for individual print categories permits the recording of page counts for specific types of printing tasks, such as the total number of color pages, monochrome pages, letter size pages, legal size pages, transparencies, etc., that may be printed. In addition to recording page counts, non-volatile memory modules may be packaged with reservoirs such as ink or toner cartridges, and the memory modules may contain one or more bit fields for recording the depletion of the reservoirs. By comparison, each bit field may be in either an erased or programmed state (e.g., a “0” or “1”) while each page count may include a plurality of bits representing a numeric value. As an example, a non-volatile memory module provided with a toner cartridge may contain thirty-two bit fields, and as a particular amount of toner has been depleted (e.g., 1/32 of the total toner), a bit field may be “punched out,” thereby changing the bit field from an erased state to a programmed state. For instance, the value in the bit field may be changed from an initial value of “0” to a value of “1”. In this illustrative example, all thirty-two bit fields may be punched out after all of the toner had been depleted, thereby signifying full depletion of the toner cartridge. It will be appreciated by one of ordinary skill in the art that imaging and printing devices may contain non-volatile memory modules that have one or more counts, resource bit fields, or a combination thereof.
A disadvantage of the method described above is that when a bit in a memory field is punched there may be a permanent change. Therefore, if a user desires to reuse, refill, or otherwise recycle the device, the permanent punched bits may prevent the device from operating properly. Also, the user may have other reasons to be able to change the information stored in the punch bit field.
Furthermore, original equipment manufacturers (OEMs) may utilize the punch bit field in order to prevent the use of cartridges made by other manufacturers. Also, the OEMs may use the punch bit field to try and prevent remanufacturers from recycling an old print cartridge. This may be done because the punch bit field can be set to indicate that a printer cartridge is in a condition where it is not presently useable such as: expired, out of ink or toner, unauthorized for a particular model, unauthorized for a particular brand, or unauthorized for a particular geographic region.